Electronic structure factors and the importance of adsorbate effects in chemisorption on surface alloys

Abstract

The chemisorption energy is an integral aspect of surface chemistry, central to numerous fields such as catalysis, corrosion, and nanotechnology. Electronic-structure-based methods such as the Newns-Anderson model are therefore of great importance in guiding the engineering of material surfaces with optimal properties. However, existing methods are inadequate for interpreting complex, multi-metallic systems. Herein, we introduce a physics-based chemisorption model for alloyed transition metal surfaces employing primarily metal d-band properties that accounts for perturbations in both the substrate and adsorbate electronic states upon interaction. Importantly, we show that adsorbate-induced changes in the adsorption site interact with its chemical environment leading to a second-order response in chemisorption energy with the d-filling of the neighboring atoms. We demonstrate the robustness of the model on a wide range of transition metal alloys with O, N, CH, and Li adsorbates yielding a mean absolute error of 0.13 eV versus density functional theory reference chemisorption energies.

Assessing Catalytic Rates of Bimetallic Nanoparticles with Active Site Specificity - A Case Study using NO Decomposition

“…These variations can, to first order, be described by a shift of the upper band edge of the d-states, as discussed elsewhere, 69 with a second-order correction based on the d-band filling of the neighboring atoms. 70 Figure 3 shows that the 𝐵𝐸 ̅̅̅̅ 𝑀 of monometallic Pt 9-9-9 is ~2.2 eV too negative compared to the volcano peak. Alloying Pt with, e.g., Au, however, results in less negative 𝐵𝐸 ̅̅̅̅ 𝑀 , thus shifting the ensemble closer to the volcano peak.…”

“…This is corrected to second order by the d-band filling of the neighboring atoms reflecting the ability of the surroundings to adopt to perturbations induced by the Pt site. 70 The volcano peak corresponding to the highest possible turnover for an active site is not reached for any of the alloying systems, which all remain on the low 𝐵𝐸 ̅̅̅̅ 𝑀 leg.…”

“…is augmented with a second-order term for the filling of neighboring surface and subsurface transition metal atoms. 70 Future models should aim at incorporating these effects.…”

Reactivity of Single-Atom Alloys as Easy as Counting to Ten

“…Although the d-band model has shown great success in understanding catalytic performance over a few decades, there are known limitations. For example, SAAs and the related class of near surface alloys (NSAs) can both escape the trends expected from the d-band model (9)(10)(11)(12). Recent developments have shown that NSAs follow stability rules and require corrections to the d-band model to fully describe their properties (9,13).…”

“…For example, SAAs and the related class of near surface alloys (NSAs) can both escape the trends expected from the d-band model (9)(10)(11)(12). Recent developments have shown that NSAs follow stability rules and require corrections to the d-band model to fully describe their properties (9,13). But such an approach is not applicable to SAAs.…”